1. Field of the Invention
The present disclosure relates to a liquid ejection head which carries out a recording operation by ejecting liquid, such as ink, and a method of manufacturing the liquid ejection head.
2. Description of the Related Art
A liquid ejection head which ejects liquid, such as ink, is consist of a recording element board and an electrical wiring tape. The recording element board is provided with ejection ports through which the liquid is ejected, liquid flow paths along which the liquid is supplied to the ejection ports, and an energy generator which generates energy that causes the ejection of the liquid.
In such a liquid ejection head, as illustrated in FIG. 7A, connecting points 204 at which a recording element board 201 and an electrical wiring tape 210 are electrically connected to each other is provided at both ends of the recording element board 201. The connecting points 204 are covered with a sealing agent 231 for the protection from liquid, such as ink, as illustrated in FIG. 7B. In the process of applying the sealing agent 231, as illustrated in FIG. 7C, portions 232 at which the amount of the applied sealing agent 231 is small (hereinafter, referred to as recesses 232) may be formed partially in the sealing agent 231. Formation of the recesses will be described with respect to FIGS. 8, and 9A to 9C. FIG. 8 is a schematic diagram illustrating a VIII-VIII cross section of FIG. 7A. As illustrated in FIG. 8, the electrical wiring tape 10 is disposed at a position higher than a recording element board 1. In this state, a needle 20 for applying a sealing agent is operated to scan and the sealing agent 31 is applied to electrical connecting portions. The needle is moved to scan positions 201, 202 and 203 in this order and apply the sealing agent. The sealing agent is applied to the electrical wiring tape 10 at the position 201, and is applied to the recording element board 1 at the position 203. At the position 202 which is a stepped portion formed between the electrical wiring tape 10 and the recording element board 1, the sealing agent discharged from the needle does not reach the recording element board 1. Since the sealing agent reaches the recording element board slowly at that position, the amount of the sealing agent at the portion is insufficient and the recess 232 is formed. Formation of the recess at the stepped portion between the electrical wiring tape 10 and the recording element board 1 is illustrated in perspective views in FIGS. 9A to 9C.
Japanese Patent Laid-Open No. 2008-296574 addresses the recess issue by increasing a gap L between the recording element board 1 and the electrical wiring tape 10 which faces the recording element board, as illustrated in FIG. 10. The increased gap L enables application of the sealing agent to side ends of the recording element board 1. Therefore, the sealing agent is applied so as not cause any insufficiency in the amount of the sealing agent applied to the recording element board 1.
However, the increased gap L requires a wider range in which the sealing agent is to be applied, and the amount of the sealing agent to be applied is increased. Further, the size of the liquid ejection head is increased corresponding to the increased application range of the sealing agent.